nounDate: 14th century1. the action of perturbing ; the state of being perturbed
2. a disturbance of motion, course, arrangement, or state of equilibrium; especially a disturbance of the regular and usually elliptical course of motion of a celestial body that is produced by some force additional to that which causes its regular motion
• perturbationaladjective

Perturbation — or perturb may refer to any of numerous concepts in several fields:* Perturbation theory, mathematical methods that give approximate solutions to problems that cannot be solved exactly * Perturbation (geology), changes in the nature of alluvial… … Wikipedia

Perturbation — Per tur*ba tion, n. [L. perturbatio: cf. F. perturbation.] 1. The act of perturbing, or the state of being perturbed; esp., agitation of mind. [1913 Webster] 2. (Astron.) A disturbance in the regular elliptic or other motion of a heavenly body,… … The Collaborative International Dictionary of English